Many electronic communications, such as electronic mail messages, benefit from the use of distribution lists. Distribution lists, for example, allow senders of electronic communications to address communications to complete groups of people without having to enter individual addresses for each member of the group. For instance, if a person needs to communicate information to all employees of his or her organization, he or she may prepare an electronic mail message addressed to a distribution list that contains electronic mail addresses for all employees of the organization. Similarly, if a manager desires to communicate information to all employees in his or her department, he or she may prepare an electronic mail message addressed to a distribution list that contains electronic mail addresses for all employees in his or her department. Not only is there time saved by not having to input many individual addresses, but communications appear tidier when tens, hundreds, or even more email addresses are replaced by an address of a distribution list. Moreover, the use of distribution lists allows communications to be directed to specific groups without the sender having to keep track of the members of the group. Thus, distribution lists are especially advantageous for groups that have dynamic membership, such as organizations or departments with a lot of employee turnover.
The conventional use of distribution lists, however, has several shortcomings. In some instances, for example, it may be desirable to exclude one or more recipients from receiving a communication. For instance, someone wishing to plan a surprise birthday party for an employee may wish to send a communication about the party to all the employees except the person for whom the party is being planned. As another example, someone may wish to send a communication about a problematic group member to all members of the group, excluding the problematic member. One way of accomplishing this is to address a communication to every person to whom receipt of the communication is intended. Another way to accomplish this, through the use of some electronic mail clients, is to enter an identifier of a distribution list in a “to:” field of an electronic message and direct the mail client to replace the identifier of the distribution list with identifiers (such as electronic mail addresses) of members of the distribution list. An electronic mail address of the person to whom distribution of the communication is not desired may be deleted from the “to:” field. These methods, however, can be quite cumbersome, especially when many people are intended to receive the communications. In addition, members of a distribution list may themselves be distribution lists and, therefore, finding the electronic mail address of a person may involve multiple replacements of distribution list identifiers with identifiers of the members of the distribution list.